Once again, a convicted killer's execution has been botched. And while that person may have been a brutal murder, the U.S. Constitution guarantees no cruel and unusual punishment.

Certainly the hour and fifty-one minutes after the injection of poison that slowly killed him must be considered cruel.

And in today's world, killing prisoners should be considered unusual. One hundred and forty other nations in the civilized world have abandoned killing prisoners.

America is among the five nations that kill the most prisoners. The other four are Iraq, Iran, China and Pakistan. Not exactly kind of company we would hope to be among for almost anything.

But if you don't believe killing prisoners is barbaric and diminishes our very humanity, there are practical reasons to stop killing prisoners.

Killing people costs a lot of money. Far more is spent to execute a person than to keep him or her in prison for life. A 2011 study found that California has spent more than $4 billion on capital punishment since it was reinstated in 1978 and that death penalty trials are 20 times more expensive than trials seeking a sentence of life in prison without possibility of parole.

No credible evidence exists that shows capital punishment deters crime. If killing criminals deterred crime, then the American South -- where 80 percent of U.S. executions take place -- would have the lowest murder rate. But the opposite is true; the South has the highest murder rates.

Even the U.S. Supreme Count admits mistakes will happen and innocent people will die. It doesn't say just how many is acceptable.

The governor of Illinois decided that none was acceptable and commuted to life in prison every death row inmate because the justice system was so flawed. In a system that rewards convictions, quite often prosecutors withheld evidence, the police didn't tell the truth and inexperienced attorneys were assigned to capital cases and didn't put up reasonable defenses.

Since the Innocence Project began in 1992, over 300 inmates have been released by introducing new evidence, including DNA testing. Almost 40 of these were capital cases, including innocent men who were scheduled to die.

Race really is a factor in determining who is sentenced to die in this country. In 1990, the then-General Accounting Office concluded that "in 82 percent of the studies [reviewed], race of the victim was found to influence the likelihood of being charged with capital murder or receiving the death penalty, i.e. those who murdered whites were more likely to be sentenced to death than those who murdered blacks."

What if, instead of spending millions on killing criminals, we could use that money to help the families who are victims put their lives back together, with therapy, counseling and restitution? Wouldn't that be a more positive, effective use of money?

In every state with the death penalty, jurors have the option of sentencing murderers to life in prison without the possibility of parole. It's cheaper to taxpayers and keeps violent offenders off the streets for good. More important, it allows mistakes to be corrected. In California, where 3,300 criminals have this sentence, seven people sentenced to life without parole have been released because they were able to prove their innocence.